1. Field of the Invention
The present invention relates to an ultrasonic diagnosis apparatus which permits various types of ultrasonic diagnostic images of a subject under examination, such as a B-mode image (a tomographic image), an M (motion)-mode image, a D-mode image (which is also called a one-point Doppler image or an FFT doppler image), a BDF-mode image (an image in which a CFM (color flow mapping) image is superimposed on a B-mode image), an MDF-mode image (an image in which a CFM image is superimposed on an M-mode image, etc., to be displayed individually or in combination.
2. Description of the Related Art
In recent ultrasonic diagnosis apparatuses, auxiliary information required for diagnosis is sometimes added to ultrasonic images such as a B-mode image, a D-mode image, an M-mode image, a BDF-mode image, an MDF-mode image, etc. By way of example, a marker indicating the position of a sampling point at which data is acquired to produce a D-mode image is superimposed on a B-mode image or a BDF-mode image. This will be described with reference to FIG. 1. That is, an ultrasonic image memory 201 for storing an ultrasonic image such as a B-mode image or a BDF-mode image, a plane memory 202 for storing auxiliary information such as a marker or a character and a mixer 203 for mixing information from these memories to produce a superimposition image are provided. Whereby, the marker and the ultrasonic image can be displayed simultaneously on a TV monitor 204.
FIG. 2 illustrates a display example in which an ultrasonic image and a marker are displayed simultaneously on the TV monitor 204. In this example, a sector-scan B-mode image 205 is displayed at the right of the screen of the TV monitor 204, and an M-mode image and a D-mode image are displayed at the lower left and the upper left, respectively, of the screen of the TV monitor 204 as shown. The M-mode image indicates variations of a part of the body of a subject under examination that corresponds to the marker 208 set on the B-mode image with time. The marker 208 is comprised of a line marker 208A and a position marker 208B which indicates the position of a sampling point set on the line marker 208A. The D-mode image 207 indicates a profile of blood flow velocity in the position of the subject corresponding to the position marker 208B. If the marker 208 is displayed simultaneously with the B-mode image 205 in this way, an operator, such as a doctor, is able to learn where the sampling point is positioned on the B-mode image. This is very helpful to diagnosis.
With such a conventional marker display, however, if the operator adjusts the brightness of the marker 208 for easier viewing when setting the position of the sampling point, the marker 208 will be an obstacle to observation of the B-mode image. If, on the other hand, the marker is adjusted so that it is not an obstacle to observation of the B-mode image, the operator will have difficulty in finding the position of the marker 208.